Image processing apparatus, image restoration method and program

Abstract

An image processing apparatus is provided which executes image restoration processing by performing a iterative computation on a degradation image. The image processing apparatus is capable of maintaining the quality of a restored image and completing the iterative computation sufficiently quickly. The first image restoration processor creates a first restored image f1 for a degradation image g by calculating an inverse filter H−1 based on Fourier transform H of a deterioration function h, multiplying the inverse filter H−1 and Fourier transform G of the degradation image g, and performing inverse Fourier transform on the result of the multiplication. The second image restoration processor creates a second restored image f2 by a iterative computation using the first restored image f1 and the deterioration function h.

Description

CROSS REFERENCE TO RELATED APPLICATIONS[0001]This application claims priority to Japanese Patent Application No. 2006-194945 filed on Jul. 14, 2006, which is incorporated herein by reference in its entirety.FIELD OF THE INVENTION[0002]The present invention relates to a technique for creating a restored image from a degradation image based on an image restoration algorithm using a deterioration function.BACKGROUND OF THE INVENTION[0003]There is conventionally known an image restoration algorithm for restoring a degradation image in the case where an image captured by an image capturing apparatus, such as a digital camera, is degradation by defocusing, blurring, aberration and the like.[0004]As the image restoration algorithm, there is known, for example, a method in which image deterioration caused by blurring at the time of image capturing is expressed by a deterioration function (point spread function (PSF)), and an image without blurring is restored on the basis of the deteriorati...

AI Technical Summary

Benefits of technology

[0010]An advantage of the present invention is to provide an image processing apparatus which performs image restoration processing on a degradation image by a iterative computation, and which is characterized by being capable of maintaining the quality of a restored image and completing the iterative computation sufficiently quickly.

[0011]According to the present invention, there is provided an image processing apparatus for creating a restored image f for a degradation image g using the captured degradation image g and a deterioration function h determined based on image capture conditions, the image processing apparatus being characterized by comprising: a first image restoration processor for executing image restoration processing by performing Fourier transform and a calculation on the degradation image g in a frequency domain to create a first restored image f1; and a second image restoration processor for executing image restoration processing by performing a iterative computation on the first restored image f1 in a real domain to create a second restored image f2 as the restored image f.

[0012]One aspect of the image processing apparatus according to the present invention, is characterized in that the first image restoration processor acquires an inverse filter H−1 based on Fourier transform H of the deterioration function h, and multiplies the inverse filter H−1 and Fourier transform G of the degradation image g, to create the first restored image f1 by performing inverse Fourier transform on the result of the multiplication, and in that the second image restoration processor creates the second restored image f2 from the first restored image f1 and the deterioration function h using a iterative computation.

[0013]One aspect of the image processing apparatus according to the present invention is characterized in that the second image restoration processor uses the first restored image f1 as an initial image of the iterative computation.

[0014]According to the present invention, there is provided an image processing apparatus for executing image restoration processing by performing a iterative computation on a degradation image, and which is capable of maintaining the quality of a restored image and completing the iterative computation sufficiently quickly.

Problems solved by technology

However, it is difficult to directly obtain f(x, y) from the formula (1).

However, in the case where diagonalization and calculation are performed based on Fourier transform, for example, pixel interpolation processing, edge processing, and the like, in which non-linear processing is performed by using local information of an image, cannot be performed.

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